Printing method and system for simulating kraft paper to print digital manuscript and computer readable storage medium

Abstract

The invention provides a printing method and a printing system for simulating kraft paper to print a digital manuscript and a computer readable storage medium. The printing method comprises the following steps: S1, determining color feature data of a pattern of a digital draft printed on real kraft paper; s2, generating a target characteristic file based on the color characteristic data; s3, simulated kraft paper color and simulated kraft paper texture are added; s4, determining CMYK four-color values for simulating the paper color of the kraft paper; and S5, based on the target characteristic file, the CMYK four-color values of the paper color of the simulated kraft paper and the texture of the simulated kraft paper, printing the digital draft to obtain the simulated kraft paper printing digital draft. According to the printing method, a standard basis is provided for printing of kraft paper, the printing effect can be guaranteed, and the complex printing process and cost can be saved.

Description

Technical Field

[0001] The present invention generally relates to the field of printing technology, and in particular to a printing method for simulating digital manuscripts printed on kraft paper, a printing system for simulating digital manuscripts printed on kraft paper, and a computer-readable storage medium. Background Art

[0002] As printed products become more and more diversified, kraft paper, as a common specialty paper, is increasingly used in the printing field. The international printing industry standard ISO 12647-7 defines the standard for digital proofing, and the applicable paper specified includes 8 categories, but kraft paper is not included. The international printing industry standard ISO 12647-2 defines the standard for traditional offset printing, and the applicable paper specified does not include kraft paper, and does not involve the printing requirements of kraft paper. Since kraft paper itself has unique coating characteristics and colors, and the international printing standards do not specify the printing standards for kraft paper, there is no relevant reference standard for the printing of kraft paper. The printing is arbitrary, it is difficult to guarantee the printing effect, and the complex printing process increases the cost. Therefore, a new technical solution is urgently needed to solve the above technical problems.

[0003] The contents of the background technology section are merely the technologies known to the inventors and do not necessarily represent the prior art in the field. Summary of the invention

[0004] In view of one or more of the problems existing in the prior art, the present invention provides a printing method for simulating kraft paper printing of digital manuscripts, comprising:

[0005] S1: Determine color characteristic data of the digital draft pattern printed on real kraft paper;

[0006] S2: generating a target characteristic file based on the color characteristic data;

[0007] S3: Add simulated kraft paper color and simulated kraft paper texture;

[0008] S4: Determine the CMYK four-color values ​​of the simulated kraft paper color; and

[0009] S5: Based on the target characteristic file, the CMYK four-color values ​​of the simulated kraft paper color and the simulated kraft paper texture, the digital draft is printed to obtain the simulated kraft paper printed digital draft.

[0010] Optionally, the step S1 includes the following sub-steps:

[0011] S11: Printing primer white ink on real kraft paper to obtain the LAB value and density value of the primer white ink that meet the preset requirements;

[0012] S12: Printing CMYK four colors on the base white ink that meets the preset requirements to obtain density values ​​of the CMYK four colors;

[0013] S13: Printing the digital draft on white paper to obtain a first sample;

[0014] S14: Printing the pattern of the digital draft on real kraft paper based on the density values ​​of the CMYK four colors and the density value of the base white ink that meets the preset requirements to obtain a second sample;

[0015] S15: Optimizing the second sample based on the first sample to obtain an optimization curve;

[0016] S16: Printing the pattern of the digital draft on real kraft paper based on the density values ​​of the four CMYK colors, the density value of the base white ink that meets the preset requirements, and the optimization curve to obtain a third sample; and

[0017] S17: Based on the third sample, obtain the color feature data.

[0018] Optionally, the step of optimizing the second sample includes: optimizing the brightness and / or chromaticity of the second sample until the brightness change is within a preset brightness change range, and / or the chromaticity change is within a preset chromaticity change range.

[0019] Optionally, the step of optimizing the brightness of the second sample includes: determining a brightness characteristic curve of the second sample; and optimizing the brightness characteristic curve until the brightness change is within the preset brightness change range.

[0020] Optionally, the brightness characteristic curve includes: a curve showing the brightness changing with dot enlargement value; the brightness change includes an average brightness change and a maximum brightness change; the brightness change includes within the preset brightness change range: the average brightness change is within a first preset range, and / or the maximum brightness change is within a second preset range.

[0021] Optionally, the step of optimizing the chromaticity of the second sample includes: determining a chromaticity characteristic curve of the second sample; and optimizing the chromaticity characteristic curve until the chromaticity change amount is within the preset chromaticity change range.

[0022] Optionally, the chromaticity characteristic curve includes: a curve of chromaticity change with dot enlargement value; the chromaticity change includes an average chromaticity change and a maximum chromaticity change; the chromaticity change within the preset chromaticity change range includes: the average chromaticity change within a first preset range, and / or the maximum chromaticity change within a second preset range.

[0023] Optionally, the first preset range includes a range less than or equal to 3; and the second preset range includes a range less than or equal to 5.

[0024] Optionally, the sub-step S17 includes the following sub-sub-steps:

[0025] S171: Collecting the TC1617 color table of the third printing sample;

[0026] S172: Based on the TC1617 color table, obtain the color feature data, where the color feature data includes a LAB value.

[0027] Optionally, step S4 includes:

[0028] S41: Determine the LAB value of the real kraft paper;

[0029] S42: Based on the LAB value of the real kraft paper, obtain the CMYK four-color values ​​of the simulated kraft paper color.

[0030] Optionally, the step S42 includes:

[0031] Convert the LAB value of the real kraft paper into CMYK four-color values ​​to obtain the CMYK four-color values ​​of the simulated kraft paper color; or

[0032] The LAB value of the real kraft paper is converted into CMYK four-color values, and the CMKY four-color values ​​are adjusted to obtain the CMKY four-color values ​​of the simulated kraft paper color.

[0033] Optionally, the step S5 includes: printing the digital manuscript on matte digital paper, and the matte degree of the matte digital paper includes a range of 1.5 to 3.5.

[0034] Optionally, the LAB value ranges of the base white ink that meets the preset requirements include 0 to 85, 0.71, and -0.35, respectively, wherein the range of L includes 83.93±1.

[0035] Optionally, the density values ​​of the four CMYK colors include 1.20±0.05, 1.21±0.05, 0.90±0.05, and 1.21±0.05, respectively.

[0036] Optionally, the LAB values ​​of the real kraft paper include 55, 11, and 24 respectively; and the CMYK four-color values ​​of the simulated kraft paper color include 27.1, 44.8, 73.5, and 11.3 respectively.

[0037] Optionally, the simulated kraft paper texture is adjustable.

[0038] The present invention also provides a printing system for simulating kraft paper printing of digital manuscripts, comprising:

[0039] A printing press configured to print the pattern of the digital draft on real kraft paper to determine color characteristic data;

[0040] a target characteristic file generating device configured to generate a target characteristic file based on the color characteristic data; and

[0041] A digital printer is connected to the target characteristic file generating device and is configured to perform the following operations:

[0042] Add simulated kraft paper color and simulated kraft paper texture;

[0043] Determine the CMYK four-color values ​​of the simulated kraft paper color; and

[0044] Based on the target characteristic file, the CMYK four-color values ​​of the simulated kraft paper color and the simulated kraft paper texture, the digital draft is printed to obtain the simulated kraft paper printed digital draft.

[0045] The present invention also provides a computer-readable storage medium, characterized in that it includes computer-executable instructions stored thereon, and the executable instructions implement the printing method as described above when executed by a processor.

[0046] The printing method of the present invention defines a set of reference standards for kraft paper printing by determining the color feature data of a digital draft pattern printed on real kraft paper. After the color feature data is determined, a target characteristic file can be generated, which can provide a reference basis for digital draft printing, solve the technical problem that kraft paper printing in the prior art is random and difficult to ensure the printing effect, and can ensure the color performance of digital draft printing. By adding simulated kraft paper color and simulated kraft paper texture, the fiber effect of the real kraft paper texture can be reproduced. By measuring the LAB value of real kraft paper, the CMYK four-color value of the simulated kraft paper color can be determined. Based on the target characteristic file, the CMYK four-color value of the simulated kraft paper color and the simulated kraft paper texture, the digital draft can be printed to obtain a digital draft of simulated kraft paper printing, which effectively saves the complex process and cost of printing on real kraft paper through a printing press, while ensuring the printing effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0048] Figure 1 A flow chart of a method for printing a digital manuscript simulating kraft paper printing according to some embodiments of the present invention is shown.

[0049] Figure 2 A flow chart showing sub-steps of step S1 according to some embodiments of the present invention is shown.

[0050] Figure 3a A schematic diagram of a first sample according to some embodiments of the present invention is shown.

[0051] Figure 3b A schematic diagram of a second sample according to some embodiments of the present invention is shown.

[0052] Figure 3c A schematic diagram of a third sample according to some embodiments of the present invention is shown.

[0053] Figure 3d A schematic diagram of a digital draft simulating kraft paper printing according to some embodiments of the present invention is shown.

[0054] Figure 4a A schematic diagram of a brightness characteristic curve (ie, a brightness optimization curve) of a brightness change amount within a preset brightness change range according to some embodiments of the present invention is shown.

[0055] Figure 4b A schematic diagram of a chromaticity characteristic curve (ie, a chromaticity optimization curve) of a chromaticity change amount within a preset chromaticity change range according to some embodiments of the present invention is shown.

[0056] Figure 5 A flow chart of sub-step S17 according to some embodiments of the present invention is shown.

[0057] Figure 6 A schematic diagram showing the addition of simulated kraft paper color according to some embodiments of the present invention.

[0058] Figure 7 A schematic diagram of simulating kraft paper texture according to some embodiments of the present invention is shown.

[0059] Figure 8 A flow chart of sub-step S4 according to some embodiments of the present invention is shown.

[0060] Fig. 9 A schematic diagram of determining CMYK four-color values ​​of simulated kraft paper color according to some embodiments of the present invention is shown.

[0061] Fig.10 A schematic diagram of a printing system for simulating kraft paper printing of digital manuscripts according to some embodiments of the present invention is shown. DETAILED DESCRIPTION

[0062] In the following, only some exemplary embodiments are briefly described. As those skilled in the art will appreciate, the described embodiments may be modified in various ways without departing from the spirit or scope of the present invention. Therefore, the drawings and descriptions are considered to be exemplary and non-restrictive in nature.

[0063] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, which are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0064] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", and "coupled" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or mutual communication; it can be directly connected, or indirectly connected through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0065] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0066] Many different embodiments or examples are provided below to realize different structures of the present invention. In order to simplify the present invention, the parts and settings of specific examples are described below. Of course, they are only examples, and the purpose is not to limit the present invention. In addition, the present invention can repeat reference numbers and / or reference letters in different examples, and this repetition is for the purpose of simplicity and clarity, which itself does not indicate the relationship between the various embodiments and / or settings discussed. In addition, the present invention provides various specific processes and examples of materials, but those of ordinary skill in the art can be aware of the application of other processes and / or the use of other materials.

[0067] The preferred embodiments of the present invention are described below in conjunction with the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0068] The present invention provides a printing method for simulating digital draft printing on kraft paper, which can provide a standard basis for printing kraft paper, ensure visual effects, and save complex printing processes and costs.

[0069] Figure 1 A flow chart of a method 1 for printing a digital manuscript simulating kraft paper printing according to some embodiments of the present invention is shown. Figure 1 As shown, the printing method 1 includes steps S1 to S5, which are described in detail below.

[0070] Step S1, determining the color characteristic data of the digital draft pattern printed on real kraft paper. Based on this step, a color reference standard basis for kraft paper printing can be formulated. Figure 2 FIG. 4 is a flow chart showing the sub-steps of step S1 according to some embodiments of the present invention. Figure 2 As shown, step S1 includes sub-steps S11 to S17:

[0071] Sub-step S11, printing primer white ink on real kraft paper, and obtaining the LAB value and density value (density) of the primer white ink that meet the preset requirements. Specifically, the primer white ink can be printed on the real kraft paper multiple times by a printing press, and the LAB value and density value of the primer white ink can be measured multiple times by a colorimeter to obtain the primer white ink that meets the preset requirements, so as to present the visual effect of standard paper white on the real kraft paper and ensure the color stability. The Lab value includes three parameters: L (brightness), a (red and green value) and b (yellow and blue value). Preferably, kraft paper with a smooth surface, no reflection and no impurities is used to ensure the accuracy and stability of the measurement results. Optionally, the density value of the primer white ink can also be measured by a densitometer. In some embodiments, the L value of the primer white ink that meets the preset requirements can be in the range of 0 to 85.

[0072] Table 1 shows the density value and LAB value of the primer white ink S that meets the preset requirements according to some embodiments of the present invention.

[0073] As shown in Table 1, the density value of the primer white ink S that meets the preset requirements is 0.23, and the Lab values ​​are 83.93, 0.71, and -0.35, respectively. The L value of the primer white ink that meets the preset requirements may have a certain margin, for example, 83.93±1. It should be noted that the density value and LAB value of the primer white ink S shown in Table 1 are only exemplary and do not constitute a limitation to the present invention.

[0074] Table 1

[0075] density L* a* b* S 0.23 83.93 0.71 -0.35 C 1.20 51.03 -25.09 -41.35 M 1.21 45.60 55.94 3.29 Y 0.90 79.08 -6.03 66.65 K 1.21 29.53 0.28 -1.29

[0076] Sub-step S12, printing CMYK four colors on the primer white ink that meets the preset requirements to obtain the density values ​​of the CMYK four colors. The CMYK four colors include cyan (Cyan, C), magenta (Magenta, M), yellow (Yellow, Y) and black (black, K). Specifically, a primer white ink that meets the preset requirements can be printed on real kraft paper by a printing press (i.e., printed based on the LAB value and density value of the primer white ink that meets the preset requirements obtained in sub-step S11), and then the CMYK four colors (four-color separation) are printed on the primer white ink that meets the preset requirements, and then a colorimeter is used to measure the density values ​​of the CMYK four colors. According to the measurement data displayed by the colorimeter, the density values ​​of the CMYK four colors can be obtained. It should be understood that the colorimeter can also measure the LAB values ​​of the CMYK four colors. It should be noted that the specifications of the real kraft paper used in sub-step S12 are the same as those of the real kraft paper used in sub-step S11.

[0077] Table 1 also shows the density values ​​and LAB values ​​of the four CMYK colors printed on the base white ink that meets the preset requirements according to some embodiments of the present invention. As shown in Table 1, the density values ​​of the four CMYK colors are 1.20, 1.21, 0.90, and 1.21, respectively. The LAB values ​​of cyan C are 51.03, -25.09, and -41.35, respectively. The LAB values ​​of magenta M are 45.60, 55.94, and 3.29, respectively. The LAB values ​​of yellow Y are 79.08, -6.03, and 66.65, respectively. The LAB values ​​of black K are 29.53, 0.28, and -1.29, respectively. The density values ​​of the four CMYK colors can have a certain margin, for example, the density values ​​of the four CMYK colors can be in the range of ±0.05. For example, the density values ​​of the four CMYK colors may include 1.20±0.05, 1.21±0.05, 0.90±0.05, and 1.21±0.05, respectively. It should be noted that the density values ​​and LAB values ​​of the four CMYK colors shown in Table 1 are only exemplary and do not constitute a limitation to the present invention.

[0078] Sub-steps S11 to S12 define the density standard for printing on kraft paper, that is, the density value of the base white ink that meets the preset requirements and the density values ​​of the four CMYK colors printed thereon. It should be understood that the visual effects presented by kraft paper treated with different processes may be somewhat different, but the density standard for printing on kraft paper can be defined by the above sub-steps S11 to S12. Preferably, the specifications of the real kraft paper used in each step of the present invention are the same to achieve consistency in the density standard, which is conducive to the final presentation of excellent visual effects. Sub-step S13, print the digital draft on white paper to obtain the first sample P1. Specifically, a digital printer can be used to print the digital draft on standard white paper to obtain the first sample P1. Figure 3a A schematic diagram of a first sample P1 according to some embodiments of the present invention is shown. The first sample P1 can be used as a reference sample for reference.

[0079] Sub-step S14, based on the density value of the primer white ink that meets the preset requirements and the density values ​​of the four CMYK colors printed on the primer white ink that meets the preset requirements, print the pattern of the digital draft on the real kraft paper to obtain the second sample P2. Specifically, for example, based on the density values ​​of the primer white ink that meets the preset requirements and the four CMYK colors printed on it that are input by the user, 0.23, 1.20, 1.21, 0.90, and 1.21, the printer prints the pattern of the digital draft on the real kraft paper to obtain the second sample P2. Figure 3b A schematic diagram of a second sample P2 according to some embodiments of the present invention is shown. It should be noted that the specification of the real kraft paper used in sub-step S14 is the same as that used in sub-steps S11 to S12.

[0080] Sub-step S15, based on the first sample P1, the second sample P2 is optimized to obtain an optimization curve. The first sample P1 is obtained by printing the digital draft on standard white paper, and the second sample P2 is obtained by printing the pattern of the digital draft on real kraft paper. By comparing the first sample P1 and the second sample P2, it can be seen that the visual effect of the cartoon presentation of the second sample P2 is not good and needs to be optimized. The specific process of optimizing the second sample P2 is described below.

[0081] In some embodiments, the step of optimizing the second sample P2 includes: optimizing the brightness and / or chromaticity of the second sample P2 until the brightness change is within a preset brightness change range, and / or the chromaticity change is within a preset chromaticity change range.

[0082] For example, the brightness of the second sample P2 can be optimized until the brightness change is within the preset brightness change range. Specifically, the three primary colors of CMY are mixed (overprinted) in different proportions to produce various gray tones from black to white, thereby determining the brightness characteristic curve of the second sample P2. The brightness characteristic curve reflects the fluctuation of the brightness, and the smaller the fluctuation, the better. After cyclic calibration of the published curve and visual evaluation (for example, referring to the first sample P1), the brightness characteristic curve is optimized until the brightness change is within the preset brightness change range, and the brightness optimization curve (such as Figure 4a When the brightness variation is within the preset brightness variation range, the brightness requirement of kraft paper printing is met.

[0083] Figure 4a FIG. 1 is a schematic diagram showing a brightness characteristic curve (i.e., brightness optimization curve) according to some embodiments of the present invention when the brightness variation is within a preset brightness variation range. Figure 4a As shown, the brightness characteristic curve can be a curve of brightness change with dot enlargement value (gray balance curve). The purple line L0 is the brightness baseline (i.e., the 0 line). The black line L1 is the curve of brightness change of black K with dot enlargement value. The orange line L2 is the curve of brightness change of the three primary colors of CMY with dot enlargement value. The brightness change wΔL* includes an average brightness change Avg and a maximum brightness change Max. The brightness change wΔL* includes the average brightness change Avg in the first preset range or the maximum brightness change Max in the second preset range within the preset brightness change range. Preferably, the brightness change wΔL* includes both the average brightness change Avg in the first preset range and the maximum brightness change Max in the second preset range within the preset brightness change range. The first preset range can be a range less than or equal to 3, i.e., a range of 0 to 3. The second preset range can be a range less than or equal to 5, i.e., a range of 0 to 5. In Figure 4a In the embodiment of FIG. 1 , the average lightness change of black K is 1.16, and the maximum lightness change is 2.40. The average lightness change of the three primary colors of CMY is 0.55, and the maximum lightness change is 1.23. However, the present invention is not limited thereto. It is understandable that although black K can be obtained by mixing the three CMY inks in equal amounts, the overprinting rate of the three CMY primary colors is difficult to reach 100%, and the insufficient purity of the three CMY inks themselves may cause errors, so directly using black ink can reduce errors and costs.

[0084] For another example, the chromaticity of the second sample P2 is optimized until the chromaticity change is within the preset chromaticity change range. Specifically, the chromaticity characteristic curve of the second sample can be determined. The chromaticity characteristic curve reflects the fluctuation of chromaticity, and the smaller the fluctuation, the better. After cyclic calibration of the published curve and visual evaluation, the chromaticity characteristic curve is optimized until the chromaticity change is within the preset chromaticity change range, and the chromaticity optimization curve (such as Figure 4b When the chromaticity variation is within the preset chromaticity variation range, the chromaticity requirement of kraft paper printing is met.

[0085] Figure 4b A schematic diagram of a chromaticity characteristic curve (i.e., chromaticity optimization curve) according to some embodiments of the present invention is shown when the chromaticity change amount is within a preset chromaticity change range. Figure 4b As shown, the chromaticity characteristic curve can be a curve of chromaticity changes with dot enlargement value. The purple line L0' is the chromaticity baseline (i.e., the 0 line). The pink line L3 is a curve of chromaticity changes of red-green value a with dot enlargement value. The blue line L5 is a curve of chromaticity changes of yellow-blue value b with dot enlargement value. The green line L4 is a curve of chromaticity changes of the three primary colors CMY with dot enlargement value. The chromaticity change wΔCh includes an average chromaticity change Avg and a maximum chromaticity change Max. The chromaticity change wΔCh includes an average chromaticity change within a first preset range or a maximum chromaticity change within a second preset range within a preset chromaticity change range. Preferably, the chromaticity change wΔCh includes both an average chromaticity change Avg within a first preset range and a maximum chromaticity change Max within a second preset range within a preset chromaticity change range. The first preset range can be a range less than or equal to 3, i.e., a range of 0 to 3. The second preset range can be a range less than or equal to 5, i.e., a range of 0 to 5. In Figure 4b In the embodiment of FIG. 1 , the average chromaticity change of the three primary colors CMY is 1.26, and the maximum chromaticity change is 2.23. However, the present invention is not limited thereto.

[0086] For another example, the brightness and chromaticity of the second sample P2 are optimized at the same time until the brightness change wΔL* is within the preset brightness change range, and the chromaticity change wΔCh is within the preset chromaticity change range. For example, the average brightness change is within the first preset range and the maximum brightness change is within the second preset range, while the average chromaticity change is within the first preset range and the maximum chromaticity change is within the second preset range. When the brightness change is within the preset brightness change range and the chromaticity change is within the preset chromaticity change range, the brightness and chromaticity requirements of kraft paper printing are met at the same time.

[0087] Sub-step S16, based on the density values ​​of the four CMYK colors, the density value of the base white ink that meets the preset requirements, and the optimization curve, the pattern of the digital draft is printed on the real kraft paper to obtain the third sample P3. Specifically, based on the density values ​​of the four CMYK colors 1.20, 1.21, 0.90, 1.21, the density value of the base white ink that meets the preset requirements 0.23, the brightness optimization curve (such as Figure 4a The black line L1 and orange line L2 shown) and the chromaticity optimization curve (as shown Figure 4b The green line L4 shown is used to print the digital draft on real kraft paper to obtain a third sample P3. Figure 3c FIG. 4 is a schematic diagram showing a third sample P3 according to some embodiments of the present invention. Figure 3a to Figure 3c As shown, the third sample P3 significantly improves the visual effect presented by the second sample P2, and is close to the first sample P1. The printing effect presented by the third sample P3 meets the requirements and has excellent color performance.

[0088] Sub-step S17, obtaining color feature data based on the third sample P3. Figure 5 FIG. 4 shows a flow chart of sub-step S17 according to some embodiments of the present invention. Figure 5 As shown, sub-step S17 includes sub-sub-steps S171 to S172. Sub-sub-step S171, collecting the TC1617 color table of the third printed sample P3. Sub-sub-step S172, based on the TC1617 color table, obtaining color feature data, that is, the optimized LAB value, that is, the LAB value of the cartoon pattern.

[0089] In some embodiments, the optimized data of some points in the third sample P3 are, for example:

[0090] 25% CMY gray light tone L is 66.2, tone a is 2.0, and b is 0.4.

[0091] 50% CMY gray light tone L is 52.1, tone a is 2.0, and b is 1.4.

[0092] 25% CMY gray light tone L is 39.6, tone a is 1.6, and b is 1.1.

[0093] 25%K gray lightens the L tone to 68.1.

[0094] 50% K gray brightens the L tone to 54.8.

[0095] 75% K gray lightens to L at 39.9.

[0096] Those skilled in the art should understand that any point of the third sample P3 will have a set of optimization data, so these optimization data are only shown for example and do not constitute a limitation to the present invention.

[0097] Through the above sub-steps S13 to S17, the brightness and color standards for kraft paper printing are defined, which provides a standard basis for kraft paper printing and can ensure the printing effect.

[0098] Step S2, based on the color feature data, generate a target feature file. Specifically, the color feature data (optimized LAB value) can be imported into a target feature file generating device, and the target feature file generating device generates a target feature file based on the color feature data obtained. In other words, the target feature file includes the LAB value of the cartoon pattern of the digital manuscript. The target feature file can be in the form of program code. The target feature file can be used later to simulate real kraft paper printing through digital printing, which can ensure the pattern effect while saving complex printing processes and costs. The following is a detailed introduction.

[0099] Step S3, adding simulated kraft paper color and simulated kraft paper texture to reproduce the effect of real kraft paper to the greatest extent. Figure 6 A schematic diagram of adding simulated kraft paper color according to some embodiments of the present invention is shown. Figure 6 As shown, the digital printer can receive the user's input command and select the Kraft paper option, thereby adding simulated kraft paper color.

[0100] In some embodiments, the simulated kraft paper texture is adjustable, including but not limited to the thickness, depth, and style of the texture, to meet personalized needs. Figure 7 Schematic diagrams of simulated kraft paper textures according to some embodiments of the present invention are shown. Figure 7 As shown, the left figure shows a simulated kraft paper texture W1, which can be used for the brown part around the cartoon pattern (e.g. Figure 3d The brown part A1 is shown in the figure on the right, and the simulated kraft paper texture W2 can be used for the light-colored part around the cartoon pattern (e.g. Figure 3d The light-colored part A2 is shown schematically). The simulated kraft paper texture can be stored in a memory or in an online database.

[0101] In step S4, the CMYK four-color values ​​of the simulated kraft paper color are determined. Step S4 includes sub-steps S41-S42. Figure 8 A flow chart of sub-step S4 according to some embodiments of the present invention is shown. Fig. 9 A schematic diagram of determining CMYK four-color values ​​of simulated kraft paper color according to some embodiments of the present invention is shown. Figure 8 and Fig. 9 As shown, step S4 includes sub-steps S41 to S42.

[0102] Sub-step S41, determining the LAB value of the real kraft paper. For example, the LAB value of the real kraft paper can be measured by a colorimeter, for example, Fig. 9 55, 11, 24 are shown on the left. The digital printer can receive input instructions from the user to import the LAB value into the digital printer.

[0103] Sub-step S42, based on the LAB value of the real kraft paper, obtain the CMYK four-color value of the simulated kraft paper color. Specifically, the digital printer can convert the LAB value of the real kraft paper into the CMYK four-color value to obtain the CMYK four-color value of the simulated kraft paper color, for example Fig. 9 27.1, 44.8, 73.5, 11.3 are shown on the right. Alternatively, after the LAB value of the real kraft paper is converted into the CMYK four-color value, the CMKY four-color value can be adjusted to obtain the CMKY four-color value of the simulated kraft paper color.

[0104] In step S5, based on the target characteristic file, the CMYK four-color values ​​of the simulated kraft paper color and the simulated kraft paper texture, the digital draft is printed to obtain the simulated kraft paper printed digital draft P4. More specifically, the target characteristic file generating device is connected to the digital printer in communication, and the target characteristic file generating device sends the target characteristic file to the digital printer. The digital printer prints the digital draft on matte digital paper based on the LAB value of the cartoon pattern in the target characteristic file, the CMYK value of the simulated kraft paper color and the simulated kraft paper texture, to obtain the simulated kraft paper printed digital draft P4. Figure 3d A schematic diagram of a digital draft P4 simulating kraft paper printing according to some embodiments of the present invention is shown. Figure 3c and Figure 3d It can be seen that the final digital draft P4 of simulated kraft paper almost perfectly reproduces the visual effect presented by the pattern P3 printed on the real kraft paper. Preferably, the matte degree of the matte digital paper can range from 1.5 to 3.5, but the present invention is not limited thereto.

[0105] The printing method of the present invention defines a set of reference standards for kraft paper printing by determining the color feature data of a digital draft pattern printed on real kraft paper. After the color feature data is determined, a target characteristic file can be generated, which can provide a reference basis for digital draft printing, solve the technical problem that kraft paper printing in the prior art is random and difficult to ensure the printing effect, and can ensure the color performance of digital draft printing. By adding simulated kraft paper color and simulated kraft paper texture, the fiber effect of the real kraft paper texture can be reproduced. By measuring the LAB value of real kraft paper, the CMYK four-color value of the simulated kraft paper color can be determined. Based on the target characteristic file, the CMYK four-color value of the simulated kraft paper color and the simulated kraft paper texture, the digital draft can be printed to obtain a digital draft of simulated kraft paper printing, which effectively saves the complex process and cost of printing on real kraft paper through a printing press, while ensuring the printing effect.

[0106] The invention also provides a printing system for simulating kraft paper printing of digital manuscripts. Fig.10 FIG. 2 is a schematic diagram of a printing system 20 for simulating kraft paper printing of digital manuscripts according to some embodiments of the present invention. Fig.10 As shown, the printing system 20 includes a printing machine 210, a target characteristic file generating device 220 and a digital printer 230. The printing machine 210 can print the pattern of the digital manuscript on real kraft paper to determine the color characteristic data. The target characteristic file generating device 220 can generate a target characteristic file based on the color characteristic data. The digital printer 230 is connected to the target characteristic file generating device 220 and can perform the following operations: adding simulated kraft paper color and simulated kraft paper texture (i.e., the above step S3). Determine the CMYK four-color values ​​of the simulated kraft paper color (i.e., the above step S4). Based on the target characteristic file, the CMYK four-color values ​​of the simulated kraft paper color and the simulated kraft paper texture, print the digital manuscript to obtain a digital manuscript printed on simulated kraft paper (i.e., the above step S5).

[0107] In some embodiments, the printing system 20 of the present invention may further include a testing instrument such as a colorimeter to measure LAB values ​​and density values.

[0108] The printing system 20 of the present invention can implement any step, sub-step, sub-sub-step and any embodiment or combination thereof in the above printing method.

[0109] In some embodiments, the printer 210 , the target profile generating device 230 and the digital printer 230 include a memory (not shown) and a processor (not shown).

[0110] In some embodiments, the memory may include a random access memory (RAM) or a non-volatile memory (NVM). Further, the memory may include at least one of a phase-change random access memory (PRAM), a static random access memory (SRAM), a dynamic random access memory (DRAM), a read-only memory (ROM), and an electrically erasable programmable read only memory (EEPROM).

[0111] In some embodiments, the processor may include a central processing unit (CPU), a microprocessing unit (MCU), and may also include other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA), complex programmable logic devices (CPLD) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components and other similar components and their peripheral circuits.

[0112] The printing system of the present invention can execute the above-mentioned printing method, and by determining the color characteristic data of the digital draft pattern printed on the real kraft paper, a set of reference standards for kraft paper printing is defined. After the color characteristic data is determined, a target characteristic file can be generated, which can provide a reference basis for the digital draft printing, solve the technical problem that the kraft paper printing in the prior art is arbitrary and difficult to ensure the printing effect, and can ensure the color performance of the digital draft printing. By adding simulated kraft paper color and simulated kraft paper texture, the fiber effect of the real kraft paper texture can be reproduced. By measuring the LAB value of the real kraft paper, the CMYK four-color value of the simulated kraft paper color can be determined. Based on the target characteristic file, the CMYK four-color value of the simulated kraft paper color and the simulated kraft paper texture, the digital draft can be printed to obtain a digital draft of simulated kraft paper printing, which effectively saves the complex process and cost of printing on real kraft paper through a printing press, while ensuring the printing effect.

[0113] The present invention also provides a computer-readable storage medium, comprising computer-executable instructions stored thereon, wherein the executable instructions implement the printing method as described above when executed by a processor.

[0114] The present invention may take the form of a computer program product implemented on one or more storage media containing program code. Computer-usable storage media include permanent and non-permanent, removable and non-removable media, and information storage may be achieved by any method or technology. The information may be computer-readable instructions, data structures, modules of a program, or other data. Examples of computer storage media include, but are not limited to: PRAM, SRAM, DRAM, other types of RAM, ROM, EEPROM, flash memory or other memory technology, compact disc read-only memory (CD-ROM), digital versatile disc (DVD) or other optical storage, magnetic cassettes, magnetic tape disk storage or other magnetic storage devices or any other non-transmission medium that can be used to store information that can be accessed by a computing device.

[0115] It should be noted that this specification provides method operations such as embodiments or schematic diagrams, but more or fewer operations may be included based on conventional or non-creative labor. The operation sequence listed in the embodiment is only one way of executing the operation sequence among many operation sequences and does not represent the only execution sequence. When the actual system or device product is executed, it can be executed in the order or in parallel according to the method sequence shown in the embodiment or flowchart.

[0116] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A printing method for simulating digital manuscript printing on kraft paper, characterized in that: include: S1: Determine color characteristic data of the digital draft pattern printed on real kraft paper; S2: generating a target characteristic file based on the color characteristic data; S3: Add simulated kraft paper color and simulated kraft paper texture; S4: Determine the CMYK four-color values ​​of the simulated kraft paper color; and S5: Based on the target characteristic file, the CMYK four-color values ​​of the simulated kraft paper color and the simulated kraft paper texture, the digital draft is printed to obtain the simulated kraft paper printed digital draft.

2. The printing method according to claim 1, characterized in that: The step S1 comprises the following sub-steps: S11: Printing primer white ink on real kraft paper to obtain the LAB value and density value of the primer white ink that meet the preset requirements; S12: Printing CMYK four colors on the base white ink that meets the preset requirements to obtain density values ​​of the CMYK four colors; S13: Printing the digital draft on white paper to obtain a first sample; S14: Printing the pattern of the digital draft on real kraft paper based on the density values ​​of the CMYK four colors and the density value of the base white ink that meets the preset requirements to obtain a second sample; S15: Optimizing the second sample based on the first sample to obtain an optimization curve; S16: Printing the pattern of the digital draft on real kraft paper based on the density values ​​of the four CMYK colors, the density value of the base white ink that meets the preset requirements, and the optimization curve to obtain a third sample; and S17: Based on the third sample, obtain the color feature data.

3. The printing method according to claim 2, characterized in that: The step of optimizing the second sample includes: optimizing the brightness and / or chromaticity of the second sample until the brightness change is within a preset brightness change range, and / or the chromaticity change is within a preset chromaticity change range.

4. The printing method according to claim 3, characterized in that: The step of optimizing the brightness of the second sample sheet comprises: determining a brightness characteristic curve of the second sample; The brightness characteristic curve is optimized until the brightness change is within the preset brightness change range.

5. The printing method according to claim 4, characterized in that: The brightness characteristic curve includes: a curve of brightness change with dot enlargement value; the brightness change includes an average brightness change and a maximum brightness change; the brightness change within the preset brightness change range includes: the average brightness change is within a first preset range, and / or the maximum brightness change is within a second preset range.

6. The printing method according to claim 3, characterized in that: The step of optimizing the chromaticity of the second sample sheet comprises: determining a chromaticity characteristic curve of the second sample; The chromaticity characteristic curve is optimized until the chromaticity change amount is within the preset chromaticity change range.

7. The printing method according to claim 6, characterized in that: The chromaticity characteristic curve includes: a curve of chromaticity change with dot enlargement value; the chromaticity change includes an average chromaticity change and a maximum chromaticity change; the chromaticity change within the preset chromaticity change range includes: the average chromaticity change within a first preset range, and / or the maximum chromaticity change within a second preset range.

8. The printing method according to claim 5 or 7, characterized in that: The first preset range includes a range less than or equal to 3; the second preset range includes a range less than or equal to 5.

9. The printing method according to claim 2 or 3, characterized in that: The sub-step S17 includes the following sub-sub-steps: S171: Collecting the TC1617 color table of the third printing sample; S172: Based on the TC1617 color table, obtain the color feature data, where the color feature data includes a LAB value.

10. The printing method according to any one of claims 1 to 7, characterized in that: The step S4 comprises the following sub-steps: S41: Determine the LAB value of the real kraft paper; S42: Based on the LAB value of the real kraft paper, obtain the CMYK four-color values ​​of the simulated kraft paper color.

11. The printing method according to claim 10, characterized in that: The sub-step S42 includes: Convert the LAB value of the real kraft paper into CMYK four-color values ​​to obtain the CMYK four-color values ​​of the simulated kraft paper color; or The LAB value of the real kraft paper is converted into CMYK four-color values, and the CMKY four-color values ​​are adjusted to obtain the CMKY four-color values ​​of the simulated kraft paper color.

12. The printing method according to any one of claims 1 to 7, characterized in that: The step S5 includes: printing the digital manuscript on matte digital paper, and the matte degree of the matte digital paper includes a range of 1.5 to 3.

5.

13. The printing method according to claim 2, characterized in that: The LAB values ​​of the primer white ink that meets the preset requirements include the range of 0 to 85, 0.71, and -0.35, respectively, wherein the range of L includes 83.93±1.

14. The printing method according to claim 2, characterized in that: The density values ​​of the four CMYK colors are 1.20±0.05, 1.21±0.05, 0.90±0.05, and 1.21±0.05, respectively.

15. The printing method according to any one of claims 1 to 7, characterized in that: The LAB values ​​of the real kraft paper are 55, 11, and 24 respectively; the CMYK four-color values ​​of the simulated kraft paper color are 27.1, 44.8, 73.5, and 11.3 respectively.

16. The printing method according to any one of claims 1 to 7, characterized in that: The simulated kraft paper texture is adjustable.

17. A printing system for simulating digital manuscript printing on kraft paper, characterized in that: include: A printing press configured to print the pattern of the digital draft on real kraft paper to determine color characteristic data; a target characteristic file generating device configured to generate a target characteristic file based on the color characteristic data; and A digital printer is connected to the target characteristic file generating device and is configured to perform the following steps: Add simulated kraft paper color and simulated kraft paper texture; Determine the CMYK four-color values ​​of the simulated kraft paper color; and Based on the target characteristic file, the CMYK four-color values ​​of the simulated kraft paper color and the simulated kraft paper texture, the digital draft is printed to obtain the simulated kraft paper printed digital draft.

18. A computer-readable storage medium, characterized in that: The invention comprises computer executable instructions stored thereon, and the executable instructions implement the printing method according to any one of claims 1 to 17 when executed by a processor.

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